1. Field of the Invention
This invention relates to a mechanical electric motor synchronizer for use in robot applications requiring precise and repeatable movements. Specifically, the present invention relates to robotics applications in which the robot is required to repeat precise movements and return to its originating point.
Robots are being used in every phase of modern life. They are being used from the assembly line of automobiles to private homes as waiters and security patrols. However, robot mobility does require means to minimize the complexity and weight of the drive mechanism. It is known in the art for designers to use a separate electric motor with a separate gear reduction system to drive each wheel. Unfortunately, even with precise manufacturing, individual electric motors will not operate identically. Consequently, robots have a tendency to drift left or right as they are moving in a straight line.
2. Description of the Prior Art
Others, outside the robotics field, have tried to synchronize two rotating wheels with no satisfactory solution. Hacker patented a vehicle drive mechanism in U.S. Pat. No. 2,126,255, issued Aug. 9, 1938, in which a combination of bevel gears and clutch mechanisms were used. Hacker discloses a complex arrangement of separate propelling means with hydraulic turbines, hydraulic reverse gears, and a plurality of brakes to operate the separate wheels. The steering wheel engages the friction clutch to make the caterpillar vehicle to run straight or turn. This type of complex system is not useable in robotics applications where there is no steering wheel.
The prior art uses electric speed governors to synchronize a robot's electric drive motors. Each independent wheel has an electronic controller which are electrically connected. The electronic controllers are designed to try and keep the wheels turning at the same torque and rpm. Unfortunately, due to the manufacturing differences in electronic controllers and variances caused by temperature fluctuations and other environmental factors, this type of synchronizer still allows the robot to drift.
Drift becomes a significant problem when a robot is required to reverse its steps and return to its original location. If drift is unaccounted for, it is impossible for the robot to return to its identical location. This problem escalates in tight maneuvering situations where the robot is physically unable to backtrack its steps due to the drift. Thus, it can be seen that the need exists for a synchronizer which will eliminate the drift in robot applications caused by the use of separate electric drive motors.